The present invention relates to the field of smoke generators. More particularly, the present invention relates to a pyrotechnic smoke generator which is flexible.
In one field of application of the present invention, although the present invention may be applied in other fields, there has been a need for a smoke generator which contains a dye which may be inserted into a pack of currency bills, where it is not readily obvious that the pack of bills contains the smoke generator. One major application of this technology today is in the field of foiling bank robberies and robberies of other financial institutions and money transporters. In the past, the center of the bill pack has been cut out and a security dye pack including a smoke generator either in the form of a plurality of rigid pellets or a plastic bag containing smoke composition were mounted in the bill pack. For example, see U.S. Pat. No. 5,059,949xe2x80x94Caparoni et al. and U.S. Pat. Nos. 5,196,828 and 5,485,143xe2x80x94Keniston.
It is very desirable in the field of currency alarm packs to provide a smoke generator along with circuitry wherein a currency alarm pack with a smoke generator and associated circuitry closely resembles a currency pack without a currency alarm pack, particularly in its feel thereby reducing the likelihood that a thief will be able to distinguish it from a real or unalarmed currency pack. In this regard, it is important that the smoke generator have lateral and torsional flexibility approaching that of a stack of currency bills of the same thickness.
One advantage of the smoke generator of the present invention is that it is very flexible having both lateral flexibility and torsional flexibility.
Another advantage of the present invention is that it may be made relatively thin and of any dimension.
Another advantage of the present invention is that it has a certain degree of elasticity due to the elastomer or silicone which enhances its flexibility.
Another advantage of the present invention is that the smoke composition, including any dye therein, is embedded, and therefore the dye and other active chemical material is not exposed thereby avoiding the possibility of getting red dye or other active chemicals dispersed about the work area.
Another advantage of the present invention is that it may be manufactured separate from the ignition source. Further, the smoke generator may be shipped separate from the electric ignition source, thereby making shipment safer and subject to less regulation.
Another advantage of the present invention is that the smoke generator of the present invention may be formed into any shape. Particularly, for use in a security currency pack, the smoke generator may be formed into a thin layer.
Another advantage of the present invention is that the thin layer smoke generator may be used in a money pack without cutting out the center of the money pack.
Briefly and basically, in accordance with the present invention, an apparatus for generating smoke is provided wherein an elastomer layer, such as a silicone layer, is formed with smoke composition particles of a predetermined size disbursed throughout the elastomer or silicone layer whereby the elastomer or silicone layer containing smoke composition particles is flexible.
In a presently preferred embodiment, the smoke composition particles have a size which will pass through a number 18 sieve, but not through a number 40 sieve.
If the flexible smoke generator is utilized as a security device in a money pack, it would be provided with a flexible circuit juxtaposed thereto as well as batteries and an antenna for receiving an activation signal.
In a presently preferred embodiment, the smoke composition particles contained in the smoke generator, when utilized for security in a currency pack, would contain a red dye. In other applications, no dye or any suitable color of dye may be utilized. In an alternative embodiment, particularly in the money pack alarm field in addition to the red dye, the smoke generator may be provided with a tear gas composition.
In an alternative embodiment, the silicone layer containing the smoke composition particles may be provided with a film on its outer surface to enhance the strength, flexibility and slidability of the silicone layer with respect to the currency bills. The outer layer of film may also provide an additional sealant for sealing the red dye and tear gas components within the silicone layer.
In another alternative embodiment, the silicone layer may be provided with reinforcing fibers to increase the strength of the silicone layer. These fibers may be any suitable fibers such as fiberglass or carbon.